Women are born with a limited ovarian reserve. That is, after birth, new eggs will no longer occur, but on the contrary, as we turn years, the amount of ovules is decreasing.
Obviously this affects our fertility, so when planning when is the best time to be a mother, it is key for women to know their ovarian reserve and make decisions with time about your motherhood.
What is the ovarian reserve?
The ovarian reserve indicates the amount of ovules available to a woman at a particular time in her life, as well as the quality of them. It is one of the indicators to assess female fertility. A low ovarian reserve (DOR) is one of the causes of female infertility.
This indicator allows women to know their level of fertility and the chances of pregnancy according to the available ovarian reserve. You will know how much you can expect to have children, as well as have room to find solutions to the risk of infertility.
AdvertisingHow many oocytes do we have?
Something that not everyone knows is that the fetus begins to manufacture eggs from nine weeks of gestation and around the fifth month of gestation already have an impressive number: about seven million oocytes (we call them oocytes because it is the name they receive immature eggs).
When we are born, however, that number drops considerably in a process called "apoptosis" whereby a programmed cell death occurs and caused by the same cells.
Then, women are born with an ovarian endowment of about a million oocytes, a number that is decreasing as we turn years.
At puberty, this amount is reduced to approximately 400,000 or 500,000 ovules. In each of the menstrual cycles that start month by month from this moment, only about 400-500 oocytes will reach ovulation.
Approximately 10% of women suffer a decrease in ovarian function earlier than normal.Ovarian reserve according to age
Each woman has her own personal circumstances that intervene when deciding when is the best time to be a mother, such as her professional career, emotional and economic stability ...
From a biological point of view WHO indicates that the safest age to conceive is situated between 20 and 24 years old.
Fertility begins to decline at 27, but it is from the age of 35 when the ovarian reserve worsens considerably.
Researchers at the University of St. Andrews confirm that from the age of 35, a woman's ovarian reserve is almost at 10% of the total. And at 40, the woman barely has quality ovules without reproductive and / or chromosomal failures, being your ovarian reserve of 3%.
From that age, the ovarian reserve continues to decrease until it runs out completely, approximately between 45 and 55 years.
Causes of low ovarian reserve
In addition to the woman's age, there are factors that can accelerate the decline in ovarian reserve, for example:
- Be a smoker or take drugs
- Chromosomal abnormalities
- Having undergone chemotherapy treatment
- Ovarian cysts caused by endomentriosis
- Genetic problems
- Immunological problems
- Benign or malignant tumors
How ovarian reserve is measured
The woman's age is a marker that determines what is the available ovarian reserve. It is logical that at older age, less ovarian reserve. However, it is an inaccurate marker.
In addition, different tests can be performed to measure ovarian reserve. You should go to a fertility specialist, who will make you an ultrasound to count the antral follicles (small sacs of fluid that contain an immature egg) and a blood test to measure the following hormones:
Follicle Stimulating Hormone (FSH)
FSH concentration should be measured between the third and fifth day of the menstrual cycle An FSH level above 10 mIU / ml indicates a low ovarian reserve.
Inhibin B
It is a hormone produced in the first half of the cycle by the cells of the outer layer of small follicles. The lower the value of inhibin B, the lower the ovarian reserve. An inhibin B value of less than 35-40 pg / ml reveals alterations in the ovarian reserve.
Estradiol
It should also be measured between the third and fifth day of the menstrual cycle. Normal estradiol values at the beginning of the cycle are less than 40 pg / ml and high values are related to a decreased ovarian reserve. However, it is not one of the best markers.
Antimüllerian hormone
The antimüllerian hormone (AMH), also called "müllerian inhibitory hormone", is a substance secreted by ovarian follicles. It is a glycoprotein that is expressed in women from puberty until it reaches menopause. The analysis of this hormone serves to see how many valid eggs the woman still has in the ovaries.
AMH levels between 0.7 and 3.5 ng / ml are considered normal. Levels below 0.7 ng / ml are associated with a decreased ovarian reserve.
Finally, a fact: if you want to know your ovarian reserve, the IVI offers women between 25 and 38 who want to plan their pregnancy a free test to calculate their ovarian reserve (here more information)
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